A prefetching strategy of streaming contents for proxy cache servers

摘要

Today, broadband access networks come into wide use and multimedia streaming services have started by many network operators. While the bandwidth available within broadband access networks is large and stabled, that available in cure networks and links between access networks and core networks is small and fluctuates in time. Thus, bandwidth bottlenecks exist between access networks and origin servers. Streaming proxy cache servers, which cache the fragments of original large multimedia contents and prefetches the rest of contents horn origin servers on demand, can stabilize the quality of the streaming service. However, the prefetching traffic of streaming contents still suffers the ordinary web traffic in the bottleneck. In this paper, we propose a prefetching strategy in which (1) a proxy prefetches the extra amount of streaming contents when the bottleneck is not congested and (2) reduces the prefetching rate as long as the prefetching buffer contents enough amount of prefetched contents to keep the quality of the streaming service. In the evaluation, we demonstrated that, under the condition that both the bandwidth of the bottleneck and the throughput of ordinary web traffic are equated, our strategy enables proxy servers to accommodate two times larger number of streaming services than existing ones do.